小麦根腐病是危害小麦根部的一种主要病害，发病时引起根部腐烂，轻者地上部分长势弱，重者死亡，严重时可减产３０％以上。小麦根腐病发生的有利环境条件是，越冬期或返青后受冻害。一般有两个高峰：（一）返青期发病。一般表现为点片发生，返青缓慢，有死苗现象；（二）返青 Wheat root rot is one of the major diseases that endanger the root of wheat. Root rot occurs when the disease occurs. The light part grows weakly on the ground, and the serious one dies. In severe cases, the yield can be reduced by more than 30%. The favorable environmental conditions for the occurrence of wheat root rot are frost damage during winter or after turning green. There are generally two peaks: (a) return to youth onset. The general performance of the spot, slow greening, dead seedlings phenomenon; (two) turn green